


Mirror Universe

by torinokomachi



Series: Shuu's collection of idea's and meta fics [2]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Canon Divergence, Angst with a Happy Ending, Canon-Typical Violence, Claudeth for Golden Deer Professor Byleth, Dimileth for Blue Lions Professor Byleth, Female My Unit | Byleth, Fire Emblem: Three Houses Blue Lions Route, Fire Emblem: Three Houses Golden Deer Route, Hurt/Comfort, Multi, Non-Chronological, Other Ships Not Mentioned in Tags, Post-Timeskip | War Phase (Fire Emblem: Three Houses), Switched Byleth AU, not a full fic
Language: English
Status: In-Progress
Published: 2020-01-16
Updated: 2020-01-16
Packaged: 2021-02-27 15:29:00
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,256
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22279429
Author URL: https://archiveofourown.org/users/torinokomachi/pseuds/torinokomachi
Summary: “I almost forgot. There is a little mishap when I helped you from the fall and it’ll take time for you to return to your true world. But these people needed you, more than ever. Even if you aren’t the same individual that they had become fond of; enough from me, now up! Up you go!”They all share the same face as the people she is familiar with, but this is not her (my) home.(In which Sothis had a little accident trying to save Byleth from the fall and by mistake, switched her with a Byleth from a different timeline. One chose the Blue Lions; the other chose the Golden Deer. Both Byleth’s struggle in a world that is similar, yet not. Regardless, they’ll help all that they could and find a way back to their original world.)(Non-chronological and some chapters may come out as a meta chapter (Not a proper chapter))
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth, My Unit | Byleth/Claude von Riegan
Series: Shuu's collection of idea's and meta fics [2]
Series URL: https://archiveofourown.org/series/1762168
Comments: 2
Kudos: 22





	1. Prelude: Far from home

In retrospect, _**she**_ should have paid attention the voice whom _**she**_ think must be Sothis herself warning _**her** _that _**she** _might end up in a world completely different from what _**she**_ remembered.

 _ **Her**_ first reaction was panic and worry for _**her** _students as soon as _**she** _woke up, learning that five years has passed after the fall of Garreg Mach Monastery.

 _ **She** _remembered the promise to meet again during the millennium festival before the ball and _**she** _headed there, hoping to see that one of the students would be there, somewhere in the Monastery.

If not, someone might be there at the Goddess Tower. So _**she** _headed there after searching for every trace of a person in the Monastery walls.

What _**she** _found was-

> **Piles of dead imperial soldiers litter around the stairs of the Goddess Tower as she made her way up.**
> 
> _Claude standing alone, watching the sunrise from the window of the Goddess Tower._

_**Her** _first thought was confusion before _**she** _slowly recalled what the voice (Sothis, or what is left of _**her** _connection with the goddess) told _**her**_ before _**she** _was forcefully awakened back into reality. _**She** _recalls the voice say:

_“I almost forgot. There is a little mishap when I helped you from the fall and it’ll take time for you to return to your true world. But these people needed you, more than ever. Even if you aren’t the same individual that they had become fond of; enough from me, now up! Up you go!”_

Confused and surprised at the sight of someone _**she** _didn't expect, _**she** _hears the person in front of _**her** _speak-

> **"Even you... Even you appeared to haunt me..."**
> 
> _"You overslept teach! Pretty rude to keep a guy waiting, don't you think?"_

This... is this what the voice meant? Was _**she** _transported to a different alternate reality where _**she** _had chosen differently?

 _ **She** _couldn't reply in the way _**she** _thought _**she** _could to the one in front of _**her**_.

Not only has five years passed by as _**she** _slept, the one in front of _**her** _are likely expecting and waiting for a different _**her**_.

As the realization sink in, she thought.

Thought of _her Claude_ ( **her Dimitri** ). Thought of _her Golden Deer_ ( **her Blue Lions** ).

 _ **She**_ thought and worry for them. Worry for a them in a world where _**she**_ did not choose them, and a them in _**her**_ original world, a world where _**she**_ did.

With the thoughts running in her mind, _**she** _decided that _**she** _shall help them for now, a war has overrun the continent in the year _**she** _is absent, and likely still happened in _**her** _home, but _**she** _also has to find a way back.

A way back to _**her**_ home.

> Part II: Verdant Moon and Azure Wind

**Notes for the Chapter:**

> Something I've been thinking, inspired by [TK_DuVeraun's prompt for the Bad Things Happen bingo](https://archiveofourown.org/works/20741174/chapters/49664873).
> 
> From here on out, the chapters will get separated into two sections, Verdant Moon involves Golden Deer Byleth who is sent to AM timeline, while Azure Wind involves Blue Lions Byleth who is sent to VW timeline.
> 
> All stories here will be written non-chronologically but I may fix that for the chronological version when this story is finished.  
> Due to myself having a different focus on main fics and busy with uni, I put up the tag that this story won't be a full fic, as in, some sections may not be a fully written chapter.
> 
> Dimitri's quote is based on the Japanese version of the reunion scene and I actually liked it a bit more than the English version (The English one is good though).
> 
> Thank you for reading and see you next time!


	2. Verdant Moon: Not (our) professor

**Summary for the Chapter:**

> Keeping the facade of playing along as a completely different version of herself isn't possible and Byleth's patience ran thin very quickly.
> 
> (Set before AM Chapter 14's mission)

**“You stay out of this!”** Shouted Dimitri at her.

She had spoken up about wanting to take the kingdom back first rather than to head straight to Enbarr, but this was Dimitri’s response.

She didn’t have a full picture of what caused Dimitri to end up the way he did, but she can only guess from what she learned from the Blue Lions who transferred to her class back in _her home_ that he might be affected by the tragedy of Duscur more than he lets on, and the war taking a toll on his mind following the fall of Garreg Mach monastery.

She wanted to take the kingdom back first. They needed more soldiers, true, but it’s the best course of option than to charge straight to the empire, lacking in numbers.

She had no wish to send her allies to an early death, but it seems Dimitri thought otherwise, obsessed with getting his revenge on Edelgard and her patience ran thin at Dimitri’s response.

“...It seems that my counsel is unwanted.” Byleth spoke up in response to Dimitri, her tone biting and cold. Taking a look at the rest of the Blue Lions along with the Knights who stare at her in their silence, she took a few steps away from them.

“I’m going to get some fresh air.” She told them and she walked her way to the stables.

There’s no way she is risking the kingdom’s fate by following Dimitri’s lead in his current state. As much as it pains her that this is what happened to Dimitri in the interval of five years, the ones that she truly missed and wished to know the whereabouts of are the Golden Deer.  _ Her Golden Deer _ .

The Alliance may remain relatively safe from what she had gathered from the Knights and Gilbert, but she doesn’t know how they would fare in this world where she never chose them.

The rest of the army would consider it risky, but it’s a risk she is willing to take.

She found a Wyvern resting amongst the other stables that Ashe and Annette had managed to save and brought back after the fall of the monastery and brought the attention of said wyvern by lightly tugging on her horn.

“Hello.” She smiled and asked. “Would you like to fly with me?”

She’s going to fly to Derdriu and find Claude.

Even if this is not the same Claude that she remembered fondly, she wants to believe that they are still the same person at the core of their souls.

***

“Ashe, did you find the professor?” Ingrid questioned sometime after the professor left the meeting at the Knight’s hall. When the meeting ended, Dimitri left and the knights scatter around the monastery while the rest of the Blue Lions decided to gather at the dining hall. Ashe himself took the duty to find the professor after she walked off.

“Oh, I did. Some of the knights saw her bonding with a Wyvern and then flew with it. She might be flying near the outskirts with the Wyvern.” Ashe had answered.

“My, that’s reassuring.” Mercedes smiled.

Sylvain, however, frowned and asked. “Since when did the professor know how to fly on a Wyvern?”

Ashe seemed confused and suggested. “The professor might have picked it up during her mercenary days.”

“No, Sylvain is onto something.” Felix interjected. “During one of our spars, the professor admitted to me in private that she had been afraid of flying after a bad experience with riding one of the mercenaries more finicky Wyvern’s in the past.”

“Plus, I never saw her train with a Wyvern, she always seem more comfortable with the horses than a Pegasus or Wyvern back in our academy days.” Sylvain added.

One by one, they came to the conclusion.

Something happened to the professor when she fell, they would have to ask her about this when she comes back.

***

The professor didn’t come back after a few days. The rest of the Blue Lions were about to send a party after her, fearing that the professor gave up on them. Just when they are getting help from some of their former classmates from the alliance and the empire who joined the Blue Lions prior to the war.

That is, until they caught sight of the professor at the entrance hall along with-

Claude?

Why would she bring Claude to the monastery?

Ingrid was the first to react. “Professor, why is Claude here?”

“We’ll need all the help we can get and I refuse to risk our allies to an early death by following Dimitri’s lead.” The professor coolly replied. She raised her hand before any of them could argue. “Before that, please gather everyone, including Dimitri. I’m about to explain something that has to do with one of the reasons to why I brought Claude to the monastery for an alliance.”

The Blue Lions looked at each other before they give an affirmation to their professor, splitting up to find the knights and Dimitri.

***

Everyone, including the Blue Lions, the knights, and students the professor had recruited into the Blue Lions gather at the cardinal room with Claude as Byleth brought a worn book with her.

They have managed to bring Dimitri in as well, Claude’s appearance in the monastery caught his interest, it seems.

Ashe was the first to ask. “Professor, what is that?”

“My father’s diary.” She answered before she gave the journal to him. “Can you read out the contents for everyone?”

Ashe sputtered. “Wha- but it’s Captain Jeralt’s diary! I can’t do that!”

“You all have my permission to know about this. I’ll show you the page where I want you to start reading.”

Ashe was skeptical at that, but nevertheless nodded since the professor  _ did  _ gave them all a permission to look into the late captain’s diary.

She opened the diary, stopping at a certain page before she handed the book to Ashe.

With a gulp, he starts.

“Day 20 of the Horsebow Moon, All is Cloudy. I can’t believe she is dead…”

Ashe continues reading for everyone, as the entries continue, all those in the room showed varying reactions of horrification, dread, and anger.

Ashe’s voice was shaken as he finished, “...I used the fire that broke out last night to fake the child’s death. Lady Rhea is in a state over the news. But I can’t change what I have done. I’ve got to take the child and leave…”

As they let the information sink in, Dorothea spoke up first. “Back then… when you said that you didn’t have a heartbeat to me… you were actually telling the truth?”

Byleth didn’t answer. Her silence must have spoken for Dorothea, for Dorothea shifted her eyes downwards. Byleth assured her. “It’s fine Dorothea, you have no way of knowing about it.”

“But professor…”

Byleth gave her a smile, looking away when the Black Eagles students gather around Dorothea before she looked back at the knights. Alois noticed her gaze first as he questioned. “Was that… was that the reason why Captain Jeralt left over twenty years ago?”

Byleth nodded.

“And whatever it is that Rhea did to you as a baby may have to do with why you came back with hair and eyes similar to Rhea’s after the mission in the sealed forest? And why she got eager to make you and the Blue Lions come to the Holy Tomb for some revelation?” Shamir questioned next.

She nodded once more.

“But what does that have to do with why the professor brought Claude into this?” Hilda asked next.

In turn, everyone in the room turned to her, waiting for her answer.

Inhale. Exhale.

She starts.

“During the fall of the monastery, I fell into a chasm and I think Sothis must have saved me to ensure my survival… but before I woke, she told me that I might end up in a world different from what I am familiar with.”

Byleth paused, taking a look into their reactions before she started again. “Five years ago,I didn’t choose the Blue Lions. I chose to teach the Golden Deer.”

“What…?”

Byleth can only give them all a somber smile. “I’m sorry, but I’m not  **your professor** .”

***

“That went well.” Claude spoke up after everyone has been dismissed. Still reeling from the shock that the  **Byleth Eisner** they knew is likely in another world and the one standing in front of them is not the professor that they are familiar with, along with her unexpected plan of allying with Claude.

“By well, you mean they’re going to be walking around eggshells on me with the knowledge and Dimitri is not going to be so compliant to hear me because I’m not **his professor**?” She drawled.

“Whoa there, what’s with the bout of sarcasm?”

Byleth shrugged. “I got it from you of course.  _ My Claude _ at least.”

Claude smiles. “Ha!  _ Other me _ must be a good role model then!”

Byleth chuckled. “No, _he’s_ a horrible one.”

“Hey! That  _ other Claude _ is also me!”

They both share a laugh for a few moments at that. Claude’s laugh faded as his expression dropped into a somber one. “Still, kinda hard to believe that there is a version of you that chose the Golden Deer five years ago.”

“But it did exist and I was sent into this world anyway.” Byleth turned to Claude.

“I’ve done the first end of my deal with you so we can work together to take down the empire now, what about yours?”

Claude brought his smile back to his lips. “I’ll return to Derdriu by sunrise and ask to see if Judith can spare some soldiers. It’s still a risky alliance though, especially with the potential that there maybe spies that Edelgard planted into the army.”

“That’s why I said that you don’t need to stay at the monastery and why I told the rest of the army to not say a word about the alliance with you until otherwise to the other soldiers. That way, Edelgard will assume that you haven’t accepted the agreement to ally with us.”

“Alright. Alright.” Claude nods before he showed his hand to her in a handshake. “Pleasure doing business with you professor.”

Byleth stared at him.

“What? I can’t exactly call you teach! I’d get you confused with  **my teach** otherwise.”

Byleth returned the handshake in response.

This is a Claude who kept himself close from everyone in a world where she chose the Blue Lions, she reminded herself, of course he wouldn’t call her “teach”, a call that becomes something endearing to hear from him.

But it’s a start.

A start to ending this war and working on finding a way back to  _ her home _ .

**Notes for the Chapter:**

> And the differences between the two Byleth's pop up.
> 
> I believe that the house Byleth chose also affect their personality and emotional growth a bit hence this characterization of Golden Deer Byleth.
> 
> See you next time!


End file.
